View Single Post
      11-15-2020, 02:04 AM   #4
jad03060
Major General
United_States
3166
Rep
6,805
Posts

Drives: X5 45e
Join Date: Aug 2018
Location: NH

iTrader: (0)

The TBN (total base number) is a bit low for only 1500-miles. https://www.blackstone-labs.com/do-i-need-a-tbn/

Many oils start out with a pretty high value. Not knowing what the oil BMW uses, this could be normal. From what I think I know, it looks like things may have been a little loose, and the TBN buffer got used up. This can happen as the rings get polished to the cylinders, and stop any blowby of exhaust gasses that can introduce acids, that the TBN buffers. You never want the TBN to get negative in an engine. Higher pressure from higher rpm before the rings fully seat could cause that to drop faster than normal.
Appreciate 2
Paladin15556.00